<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../js/vue.js"></script>
</head>
<body>
    <!-- v-bind 绑定任意html属性-->
    <!-- 1. 用于单向数据绑定，即视图层无法改变数据层 -->
    <div id="app">
        <input type="text" v-bind:value="userName">
        <p>{{userName}}</p>
    </div>
    <script>
        new Vue({
            el: '#app',
            data: {
                userName: 'lemon'
            }
        })
    </script>
</body>
</html>